Floor-nailing machine



Nov. 27, 1928.

A. A. FAWCETT FLOOR NAILING MACHINE 4 Sheets-Sheet 1 II INVENTOR.

BY W 1 W ATTORNEYS.

Filed Oct. 1927 w "Fm W Nb m m m fiwj vlmw m 6 a ma. L w u 0 a 4 m z x/.u. N. m H w c 9 n 1. m a a. A m t. F n .w A N d R h A m H A TTORNEYS.

Nov. 27 1928. 1,693,290

' A. A. FAWCETI' FLO0R MAILING cams Filed Oct. 5. 1927 4 Slzeets-Sheeiz' 3 I6 QINVENTOR.

31 WMM A TTORNEYS.

, A. A. FAWCETT FLOOR MAILING MACHINE Nov. 27, 1928.

Filed Oct. 1927 4 Sheets-Sheet 4 gi -a Patented Nov. 27, 1928.

UNITED STATES PATENT OFFICE.

ALVIN A. FAWCETT, OF SAN FRANCISCO, CALIFORNIA, AS SIGNOR OF ONE-FOURTHTO HAWLEY S. BRADSHAW, OF PIEDMONT, CALIFORNIA, AND ONE-FOURTH TOCHARLES A. BRADSHAW, AND ONE-FOURTH TO WILLIAM J. SWART, BOTH OF OAK-LAND, CALIFORNIA.

FLOOB-NAILING MACHINE.

Application filed October a, 1927. Serial m. 223,582.

My present invention relates to an automatic floor nailing machine andhas for one of its objects to provide a machine of this character whichwill be completely automatic in its operation.

A further object of my invention is to provide a reliable nail feedingmechanism which will deliver the nails one at a time to the hammer andin a proper position. It is also an object of my invention to provide ina machine of this type, means for intermittently advancing it over thefloor and also holding it stationary at the time the nails are driven.

Another object of my invention is to provide a novel driving means forthe machine which will cooperate with one of the supporting wheels andthus tend to draw the board to be nailed into its proper position.

Other objects and advantages will appear as the description proceeds.

For a better understanding of my invention, reference should be had tothe drawings, in which like numerals apply to like parts throughout theseveral views. In these drawings v Fig. 1 is a partial front elevationof a machine embodying my invention,

Fig. 2 is a sectional view taken along the line II-II of Fig. 1,

Fig. 3 is a sectional view taken along the line IIIIII of Fig. 1,

Fig. 4 is a partial sectional View of my machine taken along line IV-IVof Fig, 1,

Fig. 5 is a horizontal sectional view taken along line VV of Fig. 4,

Fig. 6 is a partial View showing the nail guides and sets in theirraised position,

Fig. 7 is a partial view of the nail guides showing the manner ofadjusting their spacs,

Fig. 8 is a perspective view of the intermediate driving element,

Fig. 9 shows a detail view of the hopper agitating member,

Fig. 10 is a partial exploded view of the nail feeding cylinder and oneof its supports,

Fig. 11 is a sectional view through the nailfeeding cylinder,

Fig. 12 is a sectional view of the nail feed iihng channels taken alongline XIIXII of Fig. 13v is arsectional view taken along line XIIIXIII ofFig. 5,

Fig. 14 shows a modified form of hammer element, and

Fig. 15 is a detail view of the nail centering means of the nailholders.

In the drawings, I have designated the nailing machine frame by thenumeral 15. The. frame 15 is supported by wheels 16 and 16 arranged atthe front and rear thereof respectively. There should preferably be twoof the wheels 16, whereas at the rear of the frame only one wheel16"will be ,necessary, the two wheels 16 at the front being desirable asthey constitute the driving wheels and thus will move the machine in astraight line and will maintain the machine parallel with the boardbeing nailed. Each of the wheels 16 has a wide flange which is engagedby a cant-hook device 17, These devices 17 rest upon the upper part ofthe wheels 16 and are held in this position by adjustable stops 18, thelocation of which determine the amount of movement imparted to thewheels 16. Each cant-hook device 17 has a radially extending arm 19which is adapted to be engaged and driven, as will hereinafter appear,bya pawl 20. The frame15 carries a motor 21 having a suitable reducinggear within a housing 22. A main shaft 23 is driven by the motor 21 bymeans of a belt 24 and carries a freely rotatable drum 25 about which aflexible cable 26 is wound. The outer end of the cable 26 passes over asheave 27 and is attached to a weight or drop hammer 28 which is adaptedtobe raised in a guide 29 as said drum 25 is rotated.

A releasing clutch mechanism connects the drum 25 to the shaft 23 and isarranged to connect said drum and shaft so that the hammer 28 will beraised and dropped during every revolution of the shaft 23, as willhereinafter be more fully pointed out. The

shaft 23 is also provided with a gear 30 which .meshes with gears 31 and32. The gear 31 is carried by a second shaft 33 and the gear 32 operatesa crank 34 to which a link is attached. This link 35 is secured to anarm 36 upon a cylindrical nail feeding device to'be hereinafter referredto in connection with Figs. 10 and 11. A pulley 37, having a belt '38,is also driven by the, shaft 23. The belt 38 in turn drives apreliminary nail feeding roller 39 and also an agitating member 10within the nail hopper. The agitating member 40 is connected to theroller 39 by means of a crank 41 and link 12 so that it reciprocateswithin the nail hopper 43 as the roller 39 is rotated. The. shaft 23, inaddition to the above, also carries a roller' l l which is adapted toengage a cam surface 45 carried by a yielding brake arm 16. The brakearm 46 is provided with a brake shoe 47 which rests lightly upon therearwheel 16and when'pressed down there upon acts as a brake to preventmovement of the machine'along the floor. The yield .ing brake arm 16 ispivoted to the frame 15 at thepoint l8 and is so arranged with itscomponent parts that the brake shoe 47 will be pressed into brakingcontact with the wheel 16 during the nail driving period only. In otherwords, this brake is arranged to function during the period when thecanthook device 17 is not operating to drivethe machine along the nailedsurface.

Returning now to the shaft 33. This shaft carries the pawl 20hereinbefore referred to and which is illustrated in Fig. 2. This pawl20 is adapted to engage the radially extending arm 19 carried by thecant-hook device 17 and operates to drive the machine in a forwarddirection a predetermined dis tance during each revolution of the shaft38. It should be pointed out here that the distance of travel will' bedetermined by the diameter of the wheel 16 and the position of thecant-hook 17 thereupon. By referring to Figs. 2 and 8, it will be seenthat this canthook 17 is made in two parts which loosely clamp aboutthe-flanges of wheel 16. As shown in this view, the device 17 ispositioned to one side of the vertical center of the wheel 16 so that itwill drop back freely when not engaged by the pawl .20. A lug or weight49 assists in this free back movement asit causes the device 17 to restconcentrically with the wheel 16 when out of engagement with the pawl 20and also provides the weight necessary to cause it to slide or drop backthereon. The adjustable stop 18 pivoted. to the frame 15 has anadjustable screw51 whereby its position can be varied to adjust; theeffective stroke of the cant-hook device 17 and therefore the amount ofmovement over the nailed surface impartedto the machine during eachguides 56-56 and nail sets 57-57 during the machine moving and nailfeeding interval, as will be'hereinafter more fully described.

Referring now to the drop hammer 28 and its operating mechanism. Thedrum 25, as shown in Fig. 4, is freely rotatable upon the shaft/23 andis caused to rotate there with by reason of a pawl or latch 58 whichengages a notch 59 on the drum. This latch is biased into engagementwith notch 59 by reason of its weight or if desired, a suitablespring'may be provided. The latch 58 extends outwardly at its other endand in the path of this outer end I arrange a stop 60 against which itengages once during every revolution of the shaft 23, The stop 60 is solocated that the cable 26 will be wound about the drum 25 to raise the hammer 28 and when the latch 58 engages the stop 60, it will disengagethe notch 59 and permit the cable 26 to unwind from the drum 25 and thuspermit the hammer 28 to drop. As the shaft 23 continues to rotate, thelatch will again engage the notch 59 and repeat the above operation.During the interval in which the hammer is being raised, the nailfeeding and machine travel operations will take place as will bedirectly described and a result, the hammer, when it drops, will drivenails into the fiooring'at a point in advance of its previous operation.7 7

By referring to Figs. 3,4, 5,6 and 7, it will be seenthat the nailguides 5656 .and nail sets 57 57 are arrangedone behind the other withrespect to the travel of the machine. The rear nail guide 56. is mountedso thatit can be moved with respect to the front guide 56. This providesfor an adjustment of the distance between the nails when driven so thatboards of different widths can be nailed, the nails passing through theboard at the same distance fron'i each edge thereof. In Fig. 7 the rearguide 56 is shown as carried by a 'member 61 which slides by reason ofan extension 62 in a support 63. The support 63 extend forward of therear guide 56 and forms a holder for the front guide 56. In Fig.- 4 itwill be seen that the nail sets 57 and 57 have a reduced lower end6at64c and an upper or body portion which square in cross section. Asillustrated in this figure of the drawings, the front nail set 57 isprovided with ahead 65 which extends over the nail set 57 and is adaptedto receive the impact of the hammer 28 and apply it to both nail sets.The head 65 has a groove 66.0n its underside which positions it upon thenail set 57' and also per mits adjustment thereof. Slots 6767 cut in thesides of each ofv the nail sets 5656 'permita nail to passtherethroughwhen the ing channels 6868 and receive the nails 1 in a manner to behereinafter more fully described in connection with the nail feedingmechanism.

Referring now to the mechanism which operates to raise the nail guides5656 and the nail sets 5757. The nail guides 56-56 and nail sets 5757'are provided with lugs 69 and 69 respectively, which are engaged by thearms 54 and 55. As these arms 54 and 55 are moved up and down by thecams 52 and 53. the guides 5656 and nail sets 57-57 will be caused torise and fall, this movement of these parts occurring while the hammer28 is in its raised position. \Vhen the nail set-s 5757 are in theirraised position, the slots 6767 will align with the nail feedingchannels 68-68 and permit nails to drop downwardly therethrough and intothe guides 5656. Nail pushers 7070 are arranged in the channels 68-68and are driven by a rack 71which engages a segment of a gear 72 carriedby the shaft 33. These pushers 7070 operate when the nail sets areraised to push nails into the slots 6767 where they fall freely intoposition. In order to return the pushers 7070 to their initial position,I provide a spring 73. When these pushers are returned to theirinoperative position, the channels 6868' will be exposed for thereception of additional nails, as shown in Figs. 4 and 5. In order topermit the aforementioned adjustment between the nail guides 5656', Iprovide a slot and screw 50 whereby the followers can be adjusted withrespect to each other so as to cooperate properly with the nail guidesin their adjusted positions. The construction of the channels 6868' andthe pushers 7070 are shown in section in Figs. 12 and 13. In thesefigures of the drawings, it will be seen that the pushers 7070 have across section of substantially the same shape as the channels 6868 andthat the pushers are moved in unison by the rack 71.

Located about and discharging respectively into the channels 6868', Ihave shown tubes or nail conveyors 7474'. These tubes connect with nailreceivers 7575 and direct the nails therefrom to the channels 68-68 asthey are deposited in the receivers 7575 by a rotating nail pickingmechanism 76. This nail picking mechanism 7 6 is illustrated in Figs. 10and 11 of the drawings. It comprises a cylindrical member 77 having aradial slot 78 cut therein. A radially movable member 79 is arrangedwithin the slot 78-and has projections 80 at its ends which engageirregular grooves or camchannels 81 located in suitable journals 82. Thejournals 82 also function to support the member 77 by reason of studshafts 83 in the ends thereof. The slot 78 is provided at its upper endwith a recess 84 which will permit a nail to'lie therein. The movablemember 79 is so arranged that it will not disturb a nail within therecess 84, but will function to prevent more than one nail being carriedover to each of the receivers 75-75. here that the picker mechanism ismade in It should be noted the form of a long cylinder and that anydifferent rate, a little faster than they are,

taken from the hopper 43. Any accumulation of nails in the hopper 43will be taken care of by the agitators 40 into which the nails aredropped. A pair of chutes 87 87 lead from the roller 39 to the agitators40 and deposit the nails therein. These agitators'40 are driven by thecrank 41 so that they will be positioned under the chutes 87 87 at thetime the nails are discharged therefrom. The agitator 40 is in the formof a rectangular ring and has no bottom. This permits the nails to slidewithin the agitator and in contact with the bottom of the hopper 43. Atthe lower end of the agitators travel. means is provided to raise theagitator slightly at its lower edge so as to permit a nail to passthereunder and to contact with the picker roller 76. This secondposition of the agitator 40 is shown in dotted lines in Fig. 9. I

In Fig. 14 of the drawings, I have shown a modified form of hammer, Inthis modi- -fication, the hammer is composed of two parts 9090. Withthis hammer, I dispense with the head 65, previously described, so thateach of the two parts of the hammer operates independently upon a singlenail set. The part 90 is arranged to be lifted by the cable 26 and has afixed key 91 which engages a slot 92 in the part 90. As the cable 26raises the part 90, the key 91 will engage the end of the slot 92 andthus lift the part 90. Upon release of the drum 25 and cable 26, the twoparts 90 and 90 will drop, the part 90 contacting first with itscooperating nail set and then the part 90 cooperating with itscorresponding nail set. In this way I provide two separate impacts foreach driving operation and thereby reduce the shockupon the floor.

In Fig. 15, I show an improvement in the nail guides 56-56. Thisimprovement resides in the provision of a pair of yielding jaws 93.These jaws are spring pressed toward the center of the nail guide andhave) only sutficient stiffness to center the nail theirproper positionalong the floor, the

1 the .(3T.6T, where they will drop downwardly machine is then set so asto travel at right angles to the'boards, the nailholders being locatedproperly over a board and the driving mechanismadjusted to propel themachine a distance equal, to the width of a board during each revolutionof the shaft 23.

Assuming further that nails are in their proper place within the nailguides 5656 and that the hammer raising mechanism is int-he positionshown in Fig.4. From this position, as the shaft 23 continues to rotate,in' a counter-clockwise direction, the latch 58, by reason of the stop60, will be pulled out of engagement with the notch 59. This willrelease the drum 25 and' cable 26, and thus permit hammer 28 to dropupon the head and impart adriving force upon the nails and force theminto the floor. During this operation the other elements of the machinehave been continuously driven. The drum 25 is immediately engaged by thelatch 58 and the hammer begins to rise again. At this point, cams 52 and53 come into play and raise the nail holders 56'56 and nail sets 57- 57.The pawl 20 engages the radial arm 19 of the cant-hook device 17 andimparts a forward movement to the machine equal to the width of a board.At the end of this movement, the, roller 44 carried by the shaft 23 willbe brought into contact with the cam surface 45 upon the brake arm 46and thus the brake shoe 4-7 will'be brought into braking contact withthe wheel 16 to thereby hold the machine stationary with respect to thefloor in this:

new position. During this interval, the nail feeding rollers 39 and 76will have rotated the roller 39, depositing a nail for each nail holderinto the chutes 87 and the agitators 4:0 and the roller 7 5 will havedeposited a nail in the receivers -75 jfrom which they will havetraveled through the tubes 7 l74; into the channels 68. During thisinterval. the nail holders 565(i will have returned, to their initialposition as the ing over the floor, this raising feature being providedto prevent'the'holders catchingon a nail, should it not be driven flush.with the floor. The cam 52, however, being of a somewhat longer areuatelength, will maintain the nail sets in a raised positionand before theyare allowed to drop, the pushers 7070 will be moved to the left asviewed in Fig. 4 to force the nails deposited within channels 68,6S intothe grooves and into their properposition, right end up,

in the guides 56- 56. .Aslthe shaft 33continues to rotate, the nail setswill be per-- tinues to rotate, the latclr 58 will again engage the stop60, release the drum 25, and permit the hammer, 28 to again drop uponthehead 65 to thereby repeat the nail driving operation. I I

From the aboveitavillbe seenthat I have produced a machinewhich,whenonceset in operation, willbe'completely automatic in both the movementefthe machine over the floor and in'the' nail feeding and drivingoperation. 7 I

\Vhile I have shown in thedrawings only one hammer and its correlatedelements, I desire to have it understood that my ma chine can beprovided with :any number of hammers as desired, the same beingarrangedand spaced along the front of the machine as viewed in Fig. 1,'thenumber and spacing of hammers. being determined by the nature of theworkfor which it-is to be applied," the shafts 23 and 33 extendingthroughout the length of the machine and being common to each naildriving unit. 'VVhile I have shown the preferred form of my invention asnow known to me, it is to be understood that various changes may be madein its construction without depar ing from the spirit of the inventionasidefined in the appended claims; 7

Having thus described my-invention, what I claim anddesire to secure byLetters Patent isf; I r

1. In a floor nailing machine, the combinationof a frameadapted totravel over the nailed surface, a 'IDOi'rOI for driving. said frame,adriving'wheel for said frame in contact with the nailed surface, acanthook device engaging the. flange of'said driving wheel, a cam drivenby said motor adapted to engage said cant-hook device to advance saidframe a predetermined distance during one revolution thereof, anda brakemechanism for holding said frame stationary when said cam is inaninoperative position.

2. In a floor nailing machine, the combination of a frame adapted totravel over the nailed surface, a motor: for driving said frame, a drophammer, a drum forraisi 11g said hammer driven bysaid motor, and aclutch mechanism cooperatingv with said drum to periodically raise andautomatically drop said hammer as said frame advances apredetermineddistance. 7 V

3. In a floornailingmachine, the combination of a frame adaptedto travelover the nailed surface, a drop hammer carried by said. frame, a motorfor driving said frame. a main shaft driven by said, motor, a releasabledrum upon said shaft for raising said drop hammer, and a drivingmechanism between said shaft and drum adapted to release said drum uponevery revolution of said shaft, whereby said hammer will automaticallyoperate in a nail driving direc tion as said frame advances over thenailed surface.

4. In a floor nailing machine, the combination of a frame adapted totravel over the nailed surface, a'motor for driving said frame, a drophammer, a drum for raising said hammer driven by said motor, a clutchmechanism cooperating with said drum to periodically raise andautomatically drop said hammer as said frame advances a predetermineddistance, a nail hopper, and means for automatically feeding nails fromsaid hopper to a driving position beneath said hammer.

5. In a floor nailing machine, the combination of a frame adapted totravel over the nailed surface, a motor for driving said frame, a drophammer, a drum for raising said hammer driven by said motor, a clutchmechanism cooperating with said drum to periodically raise andautomatically drop said hammer as said frame advances a predetermineddistance, a nail set located beneath said hammer, a nail hopper, meansfor raising said nail set, and means for feeding a nail from saidhopper, right end up, beneath said nail set, said nail set being allowedto engage said nail before said hammer drops.

6. In a floor nailing machine, the combination of an automaticallyoperating drop hammer, a plurality of nail positioning means incooperative relation with said drop hammer, a plurality of nail setsadapted to engage said nails when in a driving position, whereby saidhammer is adapted to drive a plurality of nails, and means whereby thespacing of said nail positioning means and nail sets may be varied.

ALVIN A. FAWCETT.

